Bolster swing-damper.



WILLIAM G. PRICE, OF NEW CASTLE, PENNSYLVANIA.

B OLSTER SWING-DAMPER.

Specification of Letters Patent.

Patented Nov. 26, 1907.

Application filed August 18.1906. erial No. 331.138.

T 0 all whom it may concern:

Be it known that 1, WILLIAM G. PRICE, resident of New Castle, in thecounty of Lawrence and State of Pennsylvania, have invented a new anduseful Improvement in Bolster Swing-Dampers, (Case 2;) and I do herebydeclare the following to be a full, clear, and eXact descriptionthereof.

This invention relates to railway car trucks, and more especially tomotor trucks for street railway and similar service.

The object of the invention is to provide a truck of this type havingwhat is known as a swing bolster with means for damping or graduallybringing to a stop the endwise movements of the bolster.

Motor trucks for street railway and similar service are usually providedwith a bolster which supports the car body and which is so mounted as tohave both a vertical and an endwise movement, this being most commonlyeffected by supporting the ends of the bolster upon elliptic springswhich in turn are supported by Ushaped hangers pivoted to the frame.Consequently, the bolster has an endwise movement so as to prevent thesudden shocks due to change of direction of the car body when roundingcurves, upon rough track, and the like. It is desirable, however, toprevent such extended endwise movement of the bolster as to cause thesame to strike the side frames of the truck, as this causes adisagreeable shock. I'Ieretofore friction devices have been used toprevent excessive endwise movement of the bolster, but in all priordevices of this character said devices have either interfered with thefree vertical movement of the bolster, which is desirable in order togive easy riding, or else have given nearly as great resistance on smallendwise movements of the bolster as for large. It is desirable to haveconsiderable freedom of endwise movement for the bolster when only smallmovements occur, but to have sufficient resistance against extendedmovements of the bolster to prevent the same from striking the sideframes.

This invention is intended to secure the objects just stated, namely, toprovide a bolster swing damper which does not interfere with the freevertical movements of the bol ster, and which also preferably imposeslittle or no frictional resistance to small endwise movements of thebolster, but a sufficient frictional resistance to large endwisemovements of the bolster. These objects are accomplished byjtheconstruction and arrangementjhereinafter described and claimed.

In the accompanying drawing Figure 1 is a plan view of a portion of atruck embodying my invention; Fig. 2 is a transverse section on the line22 Fig. l Fig. 3 is an oillarged plan view of the bolster and the swingdamping device in horizontal section; Fig. i. is a similar view showinga modification; and Fig. 5 is a perspective view of the friction plate.

The truck frame may be of any desirable construction, that shown havingthe side frames 1 connected by transoms 2 which are shown formed ofmetal angle bars. The bolster 3 is supported upon elliptic springs 4%held in U-shaped hangers 5 pivotally suspended from the frame. thismanner of mounting the bolster permits both vertical and endwisemovements thereof and this type is usually spoken of as a swing bolster.The bolster itself may be of any desired construction, it being shown inthe drawing as a solid beam.

Connected to the lower face of the bolster by means of bolts 7 is aplate 8 whose edge is turned upwardly to provide the vertical portion 9.Cooperating with this vertical portion is the friction plate 10 whoseends are bent at right angles to its body as at 11 and lie on eitherside of the vertical portion 9 of the bolster plate 8. The frictionplate is provided with. a longitudinal slot 10 through which passes abolt 12, said bolt also passing through a hole in the transom 2 andbeing provided on its inner end with a nut 13 and cotter pin 14.interposed between the head of the bolt and the friction plate 10 is awasher 16 and between the transom and the nut 13 on the bolt is a spiralspring 17, which normally is under sufficient compression tofrictionally clamp the plate 10 between the washer 16 and the transom 2.By means of the nut 13 the strength of the spring 17 can be adjusted soas to vary the extent of the friction on the plate 10 as desired.

It is obvious from this construction that the vertical movement of thebolster merely carries the plate 9 up and down, but without producingany movement of the friction plate 10 whatsoever and without anymaterial contact between the plate 9 and the plate 1.0. Consequentlyvertical movements of the bolster are entirely free. Should the bolster,however move endwise the upwardly It is obvious that r movements of thebolster.

turned portion 9 of the bolster plate contacts with one or the other endportions 11 of the friction plate 10 and moves said plate endwise, sothat the friction between said plate and the washer 16 and transom 2resists the endwise movement of the bolster and gradually brings thesame to rest.

In Fig. 4 I have shown a modification having the preferred functionwherein practically no, or at least only a very slight, frictionalresistance is offered to small endwise movements of the bolster butgreater frictional resistance is offered to longer endwise This iseffected by making the hole 18 in the transom 2 through which the bolt12 passes considerably larger than said bolt, so that for small endwisemovements of the plate 10 the bolt swings to the inclined position shownin Fig. 4, thus permitting the washer 16 to move with the plate 10 andrelieving the plate of the friction of said washer. Consequently thebolster is subjected to only a slight damping effect for small endwisemovements. As soon, however, as the bolt has swung to such an extentthat it comes in contact with the walls of the hole 18 it becomesstationary and the washer 16 likewise becomes stationary so that in thefurther endwise movement of the bolster the plate 10 is subjected to thefull frictional eflect of the washer 16 and tran som 2. In this way themore extended endwise movements of the bolster are subjected to anincreasing frictional resistance.

What I claim is:

1. In a car truck, the combination of a truck frame, a bolster mountedtherein for both vertical and horizontal movement, and a friction platebetween the bolster and truck frame and arranged to resist the endwisebut not the vertical movements of the bolster.

2. In a car truck, the combination of the truck frame, a bolster mountedtherein for both vertical and horizontal movement, a friction plateconnected to the frame, and connections between said friction mechanismand the bolster permitting a free vertical movement of the bolster.

3. In a car truck, the combination of transoms, a bolster mountedbetween the same for both vertical and horizontal movement, a platemovable longitudinally .of the transom and having frictional connectiontherewith, and connections between said plate and the bolster providinga free vertical movement of the bolster.

4. In a car truck, the combination of transoms, a bolster mountedbetween the same for both vertical and endwise movement, a platelongitudinally movable on the transom, a spring arranged to press saidplate against the transom, and connections between said plate and thebolster permitting a free ver tical movement of the bolster.

5. In a car truck, the combination of tran soms, a bolster mountedtherebetween for both vertical and endwise movement, a plate having africtional connection with the transom, and connections between theplate and the bolster comprising members having a vertical slidingmovement with reference to each other.

6. In a car truck, the combination of transoms, a bolster mountedtherebetween for both vertical and endwise movement, a plate having aslot and bolt connection with the transom, a washer on the bolt, aspring arranged to frictionally hold the plate between the transom andthe washer, and an angle member secured to the bolster and engaging saidfriction plate.

7. In a car truck, the combination of the truck frame, a bolster mountedtherein for both vertical and longitudinal movement, a friction platemounted on the frame by a bolt and slot connection, a Washer on thebolt, an adjustable spring surrounding the bolt and frictionallyconfining the plate between the transom and a washer, horizontalprojections on said plate, and an angle member secured to the bolsterand having a vertical portion arranged between the horizontalprojections of the plate.

8. In a car truck, the combination of a truck frame, a bolster mountedtherein for vertical and endwise movement, a friction plate providedwith a slot, a bolt passing through said slot and an opening in theframe, the hole in the frame being larger than said bolt, a springarranged to frictionallyconfine the plate between the bolt head andframe, and connections between the bolster and plate whereby the latteris moved endwise with the bolster.

9. In a car truck, the combination of the frame, a bolster mountedtherein for both vertical and endwise movement, a friction plateprovided with a slot, a bolt passing through said slot and an opening inthe frame, said opening being larger than the bolt, a washer between thebolt head and friction plate, a spring for confining the plate betweenthe washer and frame, hori-- zontal projections on the plate, and aconnecting member secured to the bolster and having a vertical portionextending between the horizontal projections of the plate.

In testimony whereof, I, the said WILLIAM G. PRICE have hereunto set myhand.

l/VILLIAM G. PRICE. l/Vitnesses M. D. VOGEL, F. VV'. WVINTER.

